The Radial Tonebone Loopbone is a powerful effects loop controller for pedal boards that allows the guitar player to insert two separate pedal effects chains and remove them when not in use. This is particularly advantageous when using older pedals that tend to add noise and cause loading problems in the signal chain. The Loopbone incorporates a superb "post effects" variable gain power booster that allows for straight signal boosting or post loop-1 or loop-2 boost for soloing.

To ensure the natural tone of the instrument is maintained, the Loopbone features Radial's unique Drag Control™ pickup load correction circuit that allows the guitarist to properly match the impedance load of any pedal board configuration with any guitar for optimum performance. Furthermore, there are no signal degrading op-amps or chips in the signal path, only 100% discreet components and Radial’s highly acclaimed Class-A circuit for natural tone and exceptional dynamics.

Besides FX-loop switching, load matching and signal boost, the Loopbone brings even more to your pedal board: a separate "always-on" tuner out circuit allows on-the-fly tuning without adding noise or load to your instrument signal, and perhaps the most innovative feature of all, Slingshot™. Slingshot is Radial's unique remote switching system that allows the Loopbone to simultaneously switch amplifier channels or other amp features or even another Slingshot equipped device, such as the Radial Headbone head switcher or Radial Cabbone speaker cabinet switcher.

Designed as a Master Control for the pedal board, the Loopbone is compact, easy to use and adds tremendous control over the pedal board making it a "must have" for tone aficionados.

Features

Master control for pedal boards

Insert & combine two separate effects loops

Built-in variable gain power booster

Unique Drag™ control pickup load correction

Separate tuner output is always on

SlingShot™ remote control output

100% discreet class-A circuit design

Ultra-compact design – easy to use

Loopbone Development
For over 50 years, guitarists have been trying achieve a balance between the flexibility of having multiple presets and dialing in the perfect tone for a particular song. This has lead hi-tech companies to develop some pretty nifty devices such as modeling and digital effects pedals. These technologies although wondrous, always seem to fall short for the purist and seem to somehow disconnect the player from his instrument. The end result is that serious guitar players inevitably yield to the allure of the venerable tube amplifier.

The holy grail of tube amps is in itself a misleading notion. As any player will attest, the closer you can get to connecting the guitar to the purity of a simple tube amp, the better the feel and the more inviting the tone. But without flexibility on stage, how can you get the job done?

For world-class concert level performers, the only solution has been an investment in expensive custom-made pedal board controllers. These allow a series of preset effect loops to be engaged using a combination pedal board and rack controller along with the prerequisite full-time guitar tech. But even at this level there are shortcomings – the more complex the system becomes, the greater the chance of it becoming a technical nightmare. The demand for smaller, more flexible systems forces engineers to use chips and op-amps which result in less than ideal tone. The fix becomes the problem and you end up chasing a point of diminishing returns.

This of course leads us to ask a few simple questions: What is it that guitarists really need? How many different tones are required to perform on stage? If the tones sway too far and wide, will the guitarist’s personality get lost? How much noise is acceptable? Where should there be compromise?

Back in 1979, Radial invented the world’s first 3-channel tube amplifier. It solved a problem. It provided the guitarist with a clean tone, a crunchy rhythm channel and a solo channel. Fast-forward 25 years and for the most part, this is still the most basic yet useful set-up. The Radial Loopbone goes back to their roots and brings forth a design that truly accomplishes what it was set out to do – provide a simple tool that allows the guitarist to achieve flexibility without compromising tone.

Basic Guitar-Pedal Setups
Consider the most basic guitar set-up: A guitar, a good distortion pedal and guitar amplifier will give you a clean tone, an overdrive and with a second channel, you can likely get a pretty good solo tone.

The problems arise as soon as you introduce more pedals.

The natural tone and relationship between the pickup and the amplifier is lost – all kinds of noise creeps into your signal path, the guitar level changes and for a fleeting moment those "do-it-all-pre-packaged modeling-systems" that just sound "good to average" become very appealing. Then you give your head a shake and ask yourself "...is there not a better way"?

The Loopbone Solution
Yes Grasshopper... there is a better way, and that way is Loopbone. Loopbone solves all the above problems by introducing a master control interface that provides alternate signal paths for your "love-'em and hate-'em" effect pedals and adds what has been called "the very finest power booster on the planet" to boot. This clever bit of design accomplishes the prerequisite "clean-rhythm-solo" setup multiplied by two.

With the Loopbone, your original guitar-to-distortion-to-amp set-up is suddenly transformed into a powerful tone control center. Effortlessly add 4 more tonal variations by simply clicking in the versatile variable-gain Class-A power boost. Add effect loops and you can create two completely different signal paths: with one dedicated to the ultimate solo patch for example, the other to weird effects. Best of all, when they're not needed, you can remove the noisy pedals from your signal chain with the click of a footwitch. Lovely!

The Loopbone is small! It fits in nicely right on your pedal board along with all of your effects. Did we mention how you can turn on and off various pedals to get set for a particular musical passage without actually hearing them until the loop is engaged? Now that’s foot power!

Slingshot™ Remote Control
If the Loopbone is truly going to be the center of the pedal board, it should be able to control other aspects of your guitar system. This triggered the concept of MIDI control without actually having to resort to taking a university course on programming. Radial calls it Slingshot™.

Slingshot is a remote control that employs the same basic functionality of the time-tested channel switching found on most guitar amplifiers. On the Loopbone, you can assign the Slingshot remote to any of the two effects loops or the power booster and when depressed, can cause a remote device to change status. You could for instance have your amp channel change when effects loop-1 is engaged. If you have a Radial Headbone, you could switch amp heads or with Cabbone, you could switch speaker cabinets and go from a 2-12 open back to a 4-12 half-stack.

Loopbone is truly a marvel that opens the door to tonal flexibility without introducing noise or altering the natural tone and dynamics of your instrument.

Product Specifications

Using the Loopbone
As with all great designs, the device should be easy to use even if the internal workings are complex. The Loopbone follows this doctrine by reducing switches and clutter to the absolute minimum so that just about anyone can use the Loopbone without an owner's manual.

Audio Path
In order to route the guitar signal to various loops without changing the volume, increasing the load on the pickup, or adding noise, it must be buffered with introduction of a pre-amplifier into the signal path. To ensure the very cleanest and most natural sounding tone, there must be no signal degrading chips or op-amps in the audio circuit – the Loopbone employs Radial's highly acclaimed 100% discreet Class-A circuit, which as serious audiophiles know, is the only choice.

The Radial engineers weren't done yet – they went one step further and equipped the Loopbone with Drag Control™, our unique load correction circuit that allows the guitarist to properly match the load on his pickup so that it replicates the tone when connecting directly to his amp. Simply brilliant!

The Ins & Outs of Loopbone's Loops
The Loopbone is a unity gain device. This means that what you put in - you will get out. This of course completely gets tossed out the window based on the type of effect device you place in the effects loops. For example, some effect pedals tend to rob signal for no apparent reason. (Tuners can be particularly bad – this is why the Loopbone has a separate tuner out.) Other pedals are so noisy, you do not know how they ever got past the research & development stage. But love 'em or hate 'em, these effects can be loads of fun and using them can often lead to some great creative tones that can spur on new ideas and make your music more interesting.

To deal with these "problem children", the Loopbone has two separate effects loops. This allows each loop to contain several different effects in a chain that can be inserted into the signal path as needed. You could for instance have five pedals in the chain, turn three on and two off to set-up a searing solo tone while playing a clean rhythm, and when the moment comes, simply engage the loop for that moment of bliss!

In order to make this work, the Loopbone employs photocell technology. This is the same time tested switching system used on old Fender amps. Photocells have the distinct advantage over relays in that they do not "snap" on causing a click, but can actually be set to ramp-up and ramp-down for completely silent switching. On the downside, photocells are much more expensive thus limiting their use to only high-end gear.

With two separate loops, you can set up two completely different effect chains. You could for instance designate one for soloing and the other for wild effects. In fact you could even turn both loops on at the same time if you wanted to combine devices and have the two worlds collide!

Augmenting Your Tone with the Booster
The Loopbone's power booster is true to one of the cardinal the rules of great sound... it employs a true Class-A circuit to boost the signal. One cannot overstate the advantages of Class-A. Although less efficient than the "easy school push-pull circuit designs", Class-A circuits are without a doubt the most natural sounding and transparent. They also require more physical space and more power, which is the reason a 15V supply is necessary instead of the typical 9V supply.

Class-A circuits employ a single buffering device to amplify the gain, thus eliminating zero-cross distortion; a nasty by-product of the usual op-amp style AB designs. By eliminating zero-cross distortion and increasing the headroom with more power and larger, discreet components, we enjoy lower phase distortion and significantly less intermodulation distortion. This yields a more natural tone, which has the distinct effect of allowing natural harmonics to flow, augmenting the tone of the amp – not fighting it with odd-harmonics.

The Power of Slingshot™ – The Un-MIDI Solution
For the past 20 years, MIDI has been the standard control interface for keyboard players. MIDI works exceptionally well in the world of synthesizers, keyboards, samplers, drum machines etc. using digital on-off signals to turn notes on and off and using voltage controlled oscillators, amplifiers (VCO's and VCAs) and digitally generated signals as their tone generators.

The guitarist has never quite adopted this technology as it is the relationship between the guitar body's resonance, the pickups, amplifier and speakers that magically combine to create the tone. Guitar strings vibrate in a magnetic field causing electron flow. There is no on-off switch. It is all analog, it is imperfect, it spits and sputters – it is alive.

But the allure of MIDI is certainly valid. Stomping on a single footswitch and having multiple devices spring into action is fascinating. This led Radial to develop Slingshot. Slingshot is a remote control system that follows the traditional method of channel and reverb switching found on most amplifiers whereby a simple contact closure is all that is required to make a device change status. The system employs a standard, everyday 1/4" guitar cable to interface between various pieces of gear.

Radial has equipped several Radial Tonebone pedals with Slingshot switching including the Loopbone, the Cabbone and the Headbone. Each pedal's Slingshot implementation has been optimized for simplicity and set in the most practical format possible. For instance the Loopbone, as a master controller, is equipped with an assignable Slingshot output to control various devices. The Headbone on the other hand, is designed to receive status changes. Cabbone is slightly different again whereby it features both a Slingshot in-put and a thru-put.

In an effort to be as universal as possible, the Loopbone is equipped with two Slingshot control switches. The first switch assigns the 1/4" jack to either ring or tip for amplifiers that employ TRS style 1/4" cables with their foot switches. The second gives you a choice between latching or non-latching (momentary) switching for amps that employ a pulse to switch their channel status.

What makes the Loopbone particularly fun is that the Slingshot remote control function may be assigned to any one of the three footswitches. This could for instance allow you to activate an effect loop and send a channel change command to your amp at the same time. Add Cabbone to your system and you could instantly switch speaker cabinets and really zero-in on the tone you are looking for.

Best of all, you can make all of these devices switch at the same time with a with a single foot action. No Tap dancing!

And Then There Was MIDI
Of course for those players that choose to employ MIDI systems as a means to get as many tonal variations as possible on stage, there is good news here too... Most MIDI controllers are equipped with contact closure style I/O connectors that can be set to receive a status change command from the Loopbone or transmit a status change to the Cabbone or Headbone.